From mboxrd@z Thu Jan 1 00:00:00 1970 Received: by rv-out-0910.google.com with SMTP id f1so1786558rvb.26 for ; Wed, 27 Feb 2008 00:11:54 -0800 (PST) Message-ID: <84144f020802270005p3bfbd04ar9da2875218ef98c4@mail.gmail.com> Date: Wed, 27 Feb 2008 10:05:04 +0200 From: "Pekka Enberg" Subject: Re: [PATCH 00/28] Swap over NFS -v16 In-Reply-To: <1204099113.6242.353.camel@lappy> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Content-Disposition: inline References: <20080220144610.548202000@chello.nl> <20080223000620.7fee8ff8.akpm@linux-foundation.org> <18371.43950.150842.429997@notabene.brown> <1204023042.6242.271.camel@lappy> <18372.64081.995262.986841@notabene.brown> <1204099113.6242.353.camel@lappy> Sender: owner-linux-mm@kvack.org Return-Path: To: Peter Zijlstra Cc: Neil Brown , Andrew Morton , Linus Torvalds , linux-kernel@vger.kernel.org, linux-mm@kvack.org, netdev@vger.kernel.org, trond.myklebust@fys.uio.no List-ID: Hi Peter, On Wed, Feb 27, 2008 at 9:58 AM, Peter Zijlstra wrote: > > 1/ I note there is no way to tell if memory returned by kmalloc is > > from the emergency reserve - which contrasts with alloc_page > > which does make that information available through page->reserve. > > This seems a slightly unfortunate aspect of the interface. > > Yes, but alas there is no room to store such information in kmalloc(). > That is, in a sane way. I think it was Daniel Phillips who suggested > encoding it in the return pointer by flipping the low bit - but that is > just too ugly and breaks all current kmalloc sites to boot. Why can't you add a kmem_is_emergency() to SLUB that looks up the cache/slab/page (whatever is the smallest unit of the emergency pool here) for the object and use that? -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org